Authorities initially responded to a report of an unconscious man in the street, but when they got there and examined the body, they realized he had been shot in the head.
Neighbors heard gunshots at around midnight, but the body of the victim was not discovered for seven hours.
The victim was described as a Hispanic man, who has not been identified.
No arrests were immediately made and there wasn't immediately a motive.
It was Staten Island's fourth homicide in the past 12 days. The other three killings appear to be linked to drug dealing.
Early Monday, a 24-year-old was fatally shot in apparent retaliation for a Nov. 7 killing of a 37-year-old drug dealer.
And on Nov. 14, a 23-year-old man was fatally shot in front of his home, a murder that is also believed to have been drug related.